Carpet seam



E. C. PITMAN May 24, 193s.

CARPET SEAM` Filed Aug.. 2. 1935 M50/able fila/6J F/EE - '4 Calpe/61965 v /mo/ub/e fibras 7 .//wofub/e fibres INVENTOR.

far/a6. Pif/22m? ATTORNEY.

Patented May 2,4, 1938 PATENT QFFICEv CARPET SEAM ,Eule c. Pitman, ulm-oft, N. J., signor to E. l. dn Pont de Nemours ik Company, Wilmington, Del., a corporation oi Delaware Application August 2, 1935, Serial No. 34,319

10 Claims. (Cl. 154-i=2)I 'Ihis invention relates to a process for joining sections of carpeting, and more particularly to a carpeting which, although comprising a plurality of sections, has the appearance and eilect of a continuous pile area.

Ihe usual practice in the manufacture of carpeting of the type comprising' a plurality of sections provides for the sewing of the edges of these sections together. This method, however, pro- A duces an unsightly seam at the junction of the joined edges and allows undue seepage of dust and dirt at this point. These conditions are also conducive to excessive wear of the pile at the seam. Many attempts have been made to `devise 15 a means for uniting adjacent edges oi' sections of carpeting to eliminate the need for sewing with its attendant undesirable results. The edges have been joined with metal staples; ilne metal wire has been woven backl and forth across the seam through the fabric weave and a heavy coat of adhesive has been applied to the back of the carpet across the seam in previous efforts to provide a joint with the desired properties. Sewing and y adhesive coatings have likewise been combined in attempts to secure an acceptableseam. An alternative method provides for a woven fabric strip adhesively amxed across the adjacent edges of the carpet sections. Certain specic defects characterize this device, chief of which is a tendy ency to excessive wear at the seam because of the greater thickness of the carpet due to the added thickness of the fabric strip on the back of the rug. the lack of desired tear strength as occasioned by the dependence of each individual 85 thread on other threads of the composite woven fabric and adverse stretching tendencies.

'Ihis invention has as an object the provision o! a composition which when applied to carpet seams or adjacent edges of designs or other deco- '40 rations set in the carpeting affords a joint that is not distinguishable from the regular weave oi the carpet, but gives an eiiect oi continuous pile area.

Another object is the provision of a composition which serva to provide a strong joint atthe seam which is highly resistant to tearing or otherwise separating the adjacent edges under normal conditions oi usage.

50 Another object of the invention is the provision o! a composition which when applied across the adjacent edges of carpet sections and suitably processed blends into the carpet backing and becomes substantially a part thereof.

Another object is the provision of an adhesive iilm which may be activated just prior to joining the edges to be joined.

A further object of the invention is the provision of a illm oi adhesive material in which is embedded a reinforcing structure comprising par- 5 alle] threads or the like laid transverse or oblique to length of the strip or film.

A further object of theinvention is the provision oi a process whereby a commercially acceptable joint for carpet seams may be obtained. 10

A still further object is the provision of a proc-v ess for joining carpet seams which eliminates raveling tendencies at the seams so joined.

A still further object of -the invention is the provision of a process for joining carpetseams 15v that is quite ilexible in practice and that may be readily utilized practically during laying oi the carpeting.

Another object of the invention is the provision fof an improved carpeting wherein the seams are 20 indistinguishable and are characterized by great resistance to tearing apart along the seam and which are quite durable under ordinary conditions of use.

A further object of the invention is the pro- '25 vision of an improved carpeting built up of sections wherein the stretching tendencies at the seam are greatly reduced. Y

Other objects will appear as the description of the invention proceeds. 30

'I'hese objects are accomplished by the application of a illm of a composition consisting essentially of nitrocellulose or equivalent and preferably containing a reinforcing structure comprising relatively strong threads or equivalent embedded in or forming part of the iilm parallel to each other and transverse or oblique to the length of the strip, to the back of the carpeting' and across the seam and activated by the use ot ya suitable medium having solvent :action to pro- 40 vide the necessary .adhesive qualities.

In the drawing, Figure 1 represents a broken plan view vJol! fa i'abric prepared according to the present invention. Figure 2 represents a plan view of a carpet seam in which insoluble bers 4 5 cross the line of abutment. Figure 3 is a plan view similar to Figure 2 except that the insoluble iibers cross the line 'of abutment at an angle. Figure 4 is a section through a piecev of carpet including the carpet seam. Figure 5 is also a 60 section through a carpet similar to Figure 4 and represents a modification in which the transverse ilbersare embedded in anadhesive.

In all the iigures, i represents soluble ilbers, 2 indicates insoluble ilbers. 3 indicates portions of II carpet the edges of which are shown as I. In Figures 4 and 5, the fabric of the carpet is shown as l, the pile is shown as i, and the backing is indicated as 1.

The preferred embodiment of the invention comprehends the utilization of a strip of woven fabric, the majority oi' the fibres of which are of the soluble type, which are activated by means of a suitable solvent and blended into the carpet backing by mutual dissolution. The original fabric strip is placed over the united edges of the carpet sections in such a manner as to permit the insoluble portion of the fabric strip to lie entirely across the seam, thus supplying reenforcement for the joint, after the soluble portion has blended into the carpet backing.

For example, a suitable woven fabric may be prepared from 600 denier nitrate rayon (a thread consisting of a plurality of spun nitrocellulose filaments) in combination with an insoluble type of tlbre such as #14 jute. Jute threads are preferred because of their non-stretching characteristics. 'I'he fibres are woven at a spacing of preferably about or 1A" although a closer spacing is not precluded and successful results may also be obtained with a spacing of V4" or greater.

It is immaterial which of the two types ci' material is warp or weft in the fabric, but it is essential that in one direction, all of the threads be of the soluble type. In the other direction, the nbres may consist entirely of the insoluble type or soluble nbres may be interspaced therewith at suitable intervals. For convenience it is Percent Pyroxylin 12.0

. Denatured alcohol 16.0 Ethyl acetate 54.0 Tolunl 3.0 Castor oil 15.0

usually desirable that the warp threads be of the soluble type.

While a nitrate rayon of 600 denier weight is indicated in the example shown above, weights between 150 and 1000 denier are suitable. Weights above and below, this limit are not, however, precluded from the scope of the invention, since the primary function of this portion cf ther fabric is to anchor the insoluble jute threads across the seam and to aid in providing an improved joint. Thus any weight of material that is manufactured commercially may be utilised in practicing the invention.

In applying the woven fabric strip composed of soluble nitrocellulose fibres and insoluble jute nbres as described above rto the butted edges of a carpet section, it is desirable to utilize also a suitable pyroxylin cement. The following example of a suitable cement is illustrative only since many other cements of this type commercially available would function similarly:

A coating of this cement is applied by means of a brush or other suitable means along the marginal edges of the hinted/carpet sections on an areav slightly greater than the width of the woven fabric, or, if desired, this cement coat may be applied to the woven' fabric itself. In either event the fabric cut to a width to extend approximately twoI inches on either side of the seam is laid along the butted edges of the carpet section and a second coatof the above cement, preferably in a more dilute condition, for example, cut

wi-withethylaoetataisappliedoverthearea fabric Strip.

ananas covered by the fabric-cementlayers. This serves to blend the soluble nitrate rayon fibres and first coat of cement into the carpet backing, becoming substantially an integral part thereof and creating an exceptionally strong joint at the carpet seam. 'Ihe insoluble bresof course, re-

main as such, but are embedded into the colloided the seam The following compositions are suited for use with cellulose acetate rayon-insoluble fibre' woven fabric, and may be utilized in the same mannerl as that described above for the composition designed speciilcally for the cellulose nitrate modiiled woven fabric.

Percent Cellulose nitrate (l5-20 sec. viscosity) 14.2 Ethyl alcohol (S. D.-23A) 6.1 Methyl alcohol 10.0 Acetone 41.9 Diacetone alcohol 15.0 Dimethyl cellosolve phthalate 12.8

This composition may also be used with the cellulose nitrate modified woven fabric.

- Percent Celluloseacetate (high viscosity) 13.5 Methyl alcohol 10.0 Acetone 53.0 Diacetone alcohol 10.0 Dibutyl phthalate 3.4 Dimethyl cellosolve phthalate 10.1.

Similarly, cement compositions may be prepared for use with cellulose ether modified woven fabrics, preferably containing as one of the ingredients a proportion of the same cellulose ether used in the fabric, and, of course, suitable proportions of active solvents, so that the soluble fibres may be dissolved and blended into the carpet backing.

Flor the heavier types of woven fabric an alternative procedure may be used. The fabric may be laid along the butted edges of the carpet sections and an active solvent such as acetone or ethylV acetate applied in amounts sufilcient to dissolve the soluble fibres and blend them into a previomly applied carpetbacking or cement coatinl.

An alternative material which may be utilized in the same manner includes a film of a soluble cellulose derivative which may optionally contain strong unjoined substantially parallel fibres such as Jute, spaced at sultablegintervals as indicatedv in the preferred spacing for the woven This nlm may be cast by any convenient means, such as is carried out in the preparation of moving picture nlm base or it may consist of sheet celluloid or be prepared in any manner known in the art. y

Although in its preferred form, the invention contemplates the inclusion of a suitable coating on the back of the carpet, which in a sense may aid in providing a superior jointA at the seam, the utilization of the compositions described herein for joining the seams of carpeting which is so fabricated as to avoid the necessity of a reenforcng backing is in nowise precluded. In fact, the compositions are readily adapted to considerable advantage for use in connection with carpeting which bears no backing, since the adhesive portion of the composition when suitably activated will readily penetrate the interstices between the weave of the carpet and develop a strong joint. In this case it isv desirable, however, to coat the edges of the carpet sections with a suitable composition such as is generally used as a carpet backing, prior to uniting the edges, in order to prevent raveling.

Films suitable for the present purpose may be composed of nitrocellulose, castor oil, with or without plasticizers, such as tricresyl phosphate and with or without resins. Flexible types of commonly available celluloid are satisfactory as is also moving picture film base, but some stiffening effects may be encountered in this case. Also lms composed of other cellulose derivatives such as cellulose acetate, cellulose ethers `(ethyl or benzyl cellulose), preferably softened with a suitable modifier, are likewise operative. rubber and synthetic or modied rubber D11- prene" (a synthetic rubber-like product), which may be dissolved with a suitable solvent andjpreferably containing reenforcing members, are also Within the purview of this invention. In this instance the carpet backing, if employed, should preferably consist of a similar type composition in order that the maximum adhesion be obtained,

although some latitude in this respect is permissible where the solvent used is mutual to both the carpet backing and the film utilized in joining the section edges such as for example benzyl cellulose and rubber type materials, where ,toluol may be used as a mutual solvent.

l An alternative procedure provides for the application of a layer of suitable cement along the marginal edges of the seam and the placing of individual reenforcing cross members in one of the several forms herein described on and in the body of the cement iilm while the cement is softened andthe application of a second coat of cement preferably more dilute to cause the reenforcing members to become embedded and anchored and to blend the soluble portion of the film into the carpet backing.

In addition tol joining the seams of rugs and carpeting, the process may be utilized for setting in designs -or other decorations in related or contrasting colors, which closely simulate the results obtained when the designs or decorations are actually woven in. 1

The reenforcing members may be laid transverse or oblique across the seam substantially parallel to each other or they may form a series of individual X units so spaced as to avoid any continuity of connection through the 'length of the seam, since forces applied in this directionv Raw The reenforcing members may be such materials as strong, fibrous threads, or ne, metal wires, preferably etched, to increase the strength of the joint and resistance to tearing through the length of the seam or from the cement.

According to my invention a soluble lm with or without suitable reenforcement may be practically utilized in joining the edges of sections of carpeting. In contradistinction to the results secured in prior art practices, this film when activated with solvents blends into and becomes substantially an integral part of the carpet backing when one is used and loses its identity as a film. This is of particular advantage in that there is practically no greater thickness developed at the carpet seam to cause undue wear at this point. In the preferred embodiment of the invention where transverse reenforcing members are included, resistance to the tear through the length of the seam is greatly enhanced. This result holds. of course, whether the reenforcing members are embedded-in a continuous film of a cellulose derivative or whether they form a part of a woven fabric a portion of which is made up of soluble fibres. In any event the soluble portion of the joining medium blends into the carpet backing composition at the area near the seam and aids in improving the strength of the joint.

The invention is also operable for carpeting of such construction that no backing is required. In this instance the soluble portion of the joining medium when suitablyv activated penetrates into and throughout the interstices of the carpet weave and thus serves to hold the edges in close and permanent contact.

The adaptation' of the present invention is not restricted to the joining of sections of carpeting. but is likewise operable in setting in of designs and decorations in related or contrasting colorsv appearance of an integrally woven carpet andl the seams normally clearly visible vvin `'products of the prior art are indistinguishable under ordinary observation: furthermore, the continuous nature of resultant joint secured by blending the joining medium into the carpet backing insures a stronger union of the carpet sections.

Another advantage is that the joint produced according to this invention is quite flexible and, therefore, does not cause stiffening of the carpet-v ing at the seam. A further advantage is that the penetration of the activated joining medium also serves to bind the weave at the edge of the seam, thus reducing raveling' tendencies and ex- ,cessive wear at this point.

The process disclosed is commercially practicable and may be employed either during the original manufacture of the rug or by an operator While laying the carpet. Stretching tendencies at the seam, a defect in carpeting of' this type heretofore available, are also greatly reduced in the present invention. l

- When employing the'reenforcing members embedded parallel to each other and across the' seam, it will be noted that each member acts.

independently to provide a cooperative result but. if any member is inadvertently broken or pulled out, the effect on the total strength of the joint is practically negligible, since the remaining members still serve to reenforce the joint and are individually not affected by the broken member.

It is apparent that many widely different embodiments of this invention may be made without departing from the spirit and scope thereof; and, therefore, it is not intended to be limited except as indicated in the appended claims.

. I claim:

1. The process of joining abutted edges of textile material which comprises applying a cement along the said edges and joining thereto a fabric strip having soluble and insoluble members, each of the latter crossing the abutted joint said cement'containing at least one ingredient which is a solvent for the said soluble members, the solvent being present in amount suillcient to -rendei the soluble members soft and adhesive.

2. Process of claim 1 in which the textile material is carpet.

3. Process of claim 1 in which the 4soluble ,fibres are prepared froma cellulose derivative. 4. Process of claim l in which the soluble bres are prepared from cellulose nitrate.

5. Process of joining abutted edges of a carpet which comprises applying a cellulose derivative backing composition to the said carpet, cementing thereto along the abutted edges forming the seam a strip of fabric having a set of members which are soluble and a set which are insoluble 7..Process of claim 5 in which the insoluble fibres are of Jute.

8. 'Ihe method of reinforcing carpet seams which comprises applying to the said carpet along ananas the edges to be joined a composition having' approximately the iollowing formula:

Per cent Pyroxylin 12. Denatured alcohol 16.0 Ethyl acetate 54.0 Toluol 3.0 Castor oil 15.0

Per cent Cellulose acetate (high viscosity) 13.5 Methyl alcohol 10.0 Acetone 53. 0 Diacetone alcohol 10. 0 Dibutyl phthalate 3. 4 Dimethyl cellosolve phthalate 10.1

applying a strip of fabric about four inches wide to the seam, said fabric having insoluble fibres running transversely to the seam and fibres soluble in cellulose derivative solvents running parallel to the said seam, and applying a coat of the same cement cut 50% with ethyl acetate to the exposed side of the said strip of fabric.

10.. Process of joining abutted edges of textile material which comprises applying along the said edges a fabric strip having soluble and insoluble" members, each of the latter crossing the abutted Joint and applying thereto a solvent for the said soluble members thereby forming a cement having embedded therein the insoluble members.

EARLE PII'MAN. 

